<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2010 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
// $Id$

/**
 +------------------------------------------------------------------------------
 * Think模板引擎解析类
 +------------------------------------------------------------------------------
 * @category   Think
 * @package  Think
 * @subpackage  Util
 * @author liu21st <liu21st@gmail.com>
 * @version  $Id$
 +------------------------------------------------------------------------------
 */
class TemplateThink
{
	/**
	 +----------------------------------------------------------
	 * 渲染模板输出
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $templateFile 模板文件名
	 * @param array $var 模板变量
	 * @param string $charset 模板输出字符集
	 * @param string $varPrefix 模板变量前缀
	 +----------------------------------------------------------
	 * @return void
	 +----------------------------------------------------------
	 */
	public function fetch($templateFile,$var,$charset) {
		if(!$this->checkCache($templateFile)) {
			// 缓存无效 重新编译
			$tpl = Think::instance('ThinkTemplate');
			// 编译并加载模板文件
			$tpl->load($templateFile,$var,$charset);
		}else{
			// 缓存有效 直接载入模板缓存
			// 模板阵列变量分解成为独立变量
			extract($var, EXTR_OVERWRITE);
			//载入模版缓存文件
			include C('CACHE_PATH').md5($templateFile).C('TMPL_CACHFILE_SUFFIX');
		}
	}

	/**
	 +----------------------------------------------------------
	 * 检查缓存文件是否有效
	 * 如果无效则需要重新编译
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $tmplTemplateFile  模板文件名
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 */
	protected function checkCache($tmplTemplateFile)
	{
		if (!C('TMPL_CACHE_ON')) // 优先对配置设定检测
		return false;
		$tmplCacheFile = C('CACHE_PATH').md5($tmplTemplateFile).C('TMPL_CACHFILE_SUFFIX');
		if(!is_file($tmplCacheFile))
		return false;
		elseif (filemtime($tmplTemplateFile) > filemtime($tmplCacheFile)) {
			// 模板文件如果有更新则缓存需要更新
			return false;
		} elseif (C('TMPL_CACHE_TIME') != -1 && time() > filemtime($tmplCacheFile)+C('TMPL_CACHE_TIME')) {
			// 缓存是否在有效期
			return false;
		}
		//缓存有效
		return true;
	}
}
?>